Foraminous body and method of producing the same



Nov. 16, 1943.

R. l.. HAR'rwL-:LL

FORAMINOUS BODY AND METHOD OF PRODUCING SAME 2 sheets-sheet 1 Filed June 3, 1941 BY Z ' ma J 7 ATTORNEY.

Nov. 16, 1943. 9 R. l.. HARTWELL 2,334,263

FORAMINOUS BDY ANDMETHOD 0F PRODUGING THE SAME y Filedy June 3. 1941 2 Sheets-Sheet 2.

INVENTOR.

Patented Nov. 16, 1943l OFFICE FGRAMINS BODY AND METHOD F PRODUCING THE SAME Ralf L. Hartwell, Orange, NVJ., assigner to Metal Textile Corporation, West Orange,l N. J., acorporation of Delaware Application-June s, 1941,'seria1No. 396,48:

(el. 21o-169) '-13 Claims. This invention relates to filter or strainer or other foraminous bodies of novel form and structure and to methods of producing the same.

This invention has for an object to provide a u foraminous lter or strainer or other body of novel form and structure which is produced from metallic open mesh fabric, said fabric being processed and compressed into a body mass of desired interstitial character, whereby to furnish a durable filter or strainer which is substantially self supporting and of a strength Well Acalculated to withstand considerable pressure without deformation, fracture or other damage.. y

In the making and use of filter or strainer bodies of metallic fabrics for the'ltration of uids, it is the general practice to employ woven wire mesh having openings sufficiently small to prevent passage of the smallest particles suspended in the fluid whereby to separate the former from the latter. In the case offluids containing suspensions of very flne `particles it is necessary to employ exceedingly ne Wire gauze or like fabrics 'to obtain required small strainer openings, frequently of two thousandths of an inch or less in size. Not only is such wire gauze or the like very. costly, but is also of but poor mechanical strength and unable to withstand any considerable pressure, being therefore short lived in use. Having these things in view, it is another object of this'invention to provide a novel form and construction of filter or strainer body which can be produced from a metallic fabrickmade of comparatively heavy gauge wire and having, initially, relatively large mesh openings, and yet said fabric being so processed and manipulated as to furnish a filter or strainer container openings or'interstices of exceedingly small size, when such are desired.

Other objects of this invention, not at this time morel particularly enumerated, willbe understood from the following detailed description of the same. l

The accompanying drawings show various em'- bodiments of this invention, including steps of the method procedure whereby the same are produced. In said drawings, Fig. v1 is a schematic view of a knitted metallic mesh fabric partially processed ready to be rolled upon itself and compressed into the ultimate lter or other foramilious body mass according to this invention; Fig. 2 is a View of the mesh fabric rolled andk deposited in dies for compressing the same, the female die being shown in section; Fig. 3 is a view similar to fabric that of Fig. 2, but showing the rolled mesh compressed tofa filter or other foraminous to bejprovided in the ultimate filter body.

body forming mass by the dies; and Fig. 4 is a perspective vview of'a completedlter or foram- `inous, body/formed from the material shown in Fig. 1. .l

Fig. 5 is a schematic view of a 'modified form and arrangement of knitted metallic mesh fabric materials from which a filter or foramnous body is to be formed; and Fig. 6 is a perspective view of the completed filter or strainerbody formed therefrom. I

Fig. 7 is a schematic view of another modified form and arrangement of knitted metallic mesh fabric materials from which a filter or foraminous body is` to be formed; and Fig. 8 is a perspective view of the finished filter or foraminous body formed therefrom. l

In` a simple embodiment of this invention, as shown in Fig. 4, the filter or foraminous body is produced as follows: 20

A strip of knitted. metallic mesh I0 of suitable width and length is provided. Such mesh strip may be knitted from round or flat wire of selected 'gauge and of a desired metal. The mesh preferably the latter. The knitted strip may be more or less loosely knit so that .the interllnked loops initially provide a comparatively open mesh material; i. e., a material having mesh openings which are initially much too large to serve as the relatively small'uid passage openings which are desired or strainer The metallic mesh strip is first run through corrugating rolls so as to form' therein successive crlmps or corrugations II extending obliquely acrossY the mesh strip at a selected angle other than degrees.- After the mesh strip I0 has been corrugated, the same is folded lengthwise upon itself to form a plurality of superposed plies,

and so that the crlmpsor corrugations of contiguous plies cross one another in non-nesting rela,- tion. The thus folded mesh strip is now tightly rolled lengthwiseupon itself into a. cylindrical body I 2 of predetermined diameter (see Fig. 2).

To complete the filter 'or strainer body, Ythe mesh cylinder `I2 is subjected to compression in the direction of its length, the mesh being disposed edgewise to the direction of compression'. This may be done in any suitable manner, but preferably by means of a stationary female die I3, in which the mesh cylinderv I2 is deposited, with which cooperates a movable male die I 4, which is adapted to enter and move downwardly through the female die so as to compress the mesh cylinder I2, and thus form the compacted ultimate iilter or strainer body A. The male die may be actuated in any suitable manner to force the same with compressive action against the mesh cylinder I2, as, e. g., by means of a hydraulic press mechanism (not shown). to the plunger of which said .male die is connected.

Asthe mesh cylinder I2 is forcibly compressed and compacted, the corrugated contiguous coils 'of the; vsame are interlockedy one with another, and the mesh is firmly compacted into a disclike body of substantial thickness,'and so as to closev the mesh openings and force the wire strands of the mesh into mutually abutting relation, whereby only very small interstices are formed adjacent intersecting portions of such abutting wire strands. thus formed intercommunicate throughout the mass of the body, and consequently the body possesses a foraminated internal structure ideal.`

ly adapted to perform the desired filteringl orl straining function.

Owing to the corrugated formation of the lstrip from which'the meshA cylinder. I2 is formed, when the latter is subjected to endwise applied pressure and compressed, the crushing down of the `A`convolute mesh strip'layers of the cylinder I2 causes the corrugate bends in the interlinked loops to Yinterweave and interlock one with another aszsaid cylinder is collapsed and flattened.

down into the compact foraminous massfwhich constitutesthe finished nlter or strainer body. Not onlydoes this producey thev ramified interstices which form the fluid passages throughthe lter-or strainer bodyf,`but .also tends. to interlace portions vof the .wire strands, of contiguous loops ofthe knitted mesh sok asv to non-separably interlock the same into a durable, strong. selfsustaining and stable body mass which is capable of withstanding considerable fluid pressure Without risk of deformation or disintegration in use.

A filter or strainer body of the character andv vmade by the procedure above described; may be produced in a lforaminous structure the openings of which are exceedingly smalL'so asvto strain from a nuid very line suspended particles. `For example. the filter or strainer body maybe made of a fabric knitted from fiat or ribbon-like wire of copper or other selected metal having a thick.

ness, e. g., `of approximately twelve ten thousandths of an inch. When such fabric ismanipulated as above described `to `produce the filter or strainer body, the openings or interstices formed at points where one ribbon-like portion intersectingly overlaps another will not exceed the thickness of said ribbon-like strand or wire, and -consequently the lter or strainer body will, in use, very efficiently separate exceedingly fine suspensions fromv a fluid passed therethrough, while nevertheless the durable, strong, non-deformable and pressure resistantcharacteristics of the body. due to the described structure thereof, are attained. I

` A somewhat modied embodiment of this invention, as shown in Fig. 6, provides a filter or strainer'body having at its` receiving face portion a comparatively coarse interstitial'structure B and at its discharge faeportion ak relatively ne interstitial structure C. The filteror'strainer body thus modified isk produced ask follows:

A strip of knitted metallic meshl made, e. g., from a round strand orwire of comparatively small gauge or of a flat or ribbon-like strand or wire of small thickness is provided. Superposed upon this mesh strip I5, soas to somewhat overlap the upper marginal portionA thereof, 'andso as The small 'interstices to extend therefrom, is a second strip of knitted metallic mesh I6 made from a round strand or Wire of relatively heavier gauge. The thus overlapped strips -I5 and I6 are. run together through corrugating rolls; the strips thereupon folded lengthwise upon themselves; and then rolled into a cylindrical body in the manner already described. The cylindrical body thus obtained is then compressed and compacted by the dies I3- I4 to thereby convert the cylindrical body into a finished disc-like filter or strainer body. Where the strips I5 and I6 overlap, the same will be interlocked together, while the free portions of the strip I6 will be compressed and compacted into a foraminous layer B of comparatively coarse interstitial structure, while the free portions of the strip I5 will be' compressed and compacted into a foraminous layer C of relatively ne interstitial structure; the two layers being interlocked together where the mesh strips of which they are composed overlap, as above stated. In this manner, a vunitary filter or strainer bodyis provided which, in use, may be positioned to dispose its coarse side for the reception of a. fluid to be strained therethrough and its ne side disposed to discharge said fluid. The coarse portion of the filter or strainer body will separate contained coarser particles from the iiuid, while the finer portion will separate the contained finer particles from said fluid. The fluid is thus caused to undergo a preliminary straining which clears the coarse particles therefrom, whereby` to prevent clogging of .the fine interstices of lter or'strainer body thereby, and thusimproving the efficiency of the filter and assuring a longer period of ef fective performance. l

Another modified embodiment of this invention, as shown in Fig. 8. provides a filter body D. having a reenforcing means E built thereinto, the same being produced as follows:

A strip of knitted metallic mesh I1 made. e. g., from a round strand or wire of selected gauge or of a fiat or ribbon-like strandA or wire of vselected thickness is f provided. Superposed upon this 'mesh strip I1, in registration with a marginal yfinished disc-like filter or strainer body. The

convolutions of the mesh strip I Bwill be imbedded to a desired depth, according'to the width thereof as compared with the width of the main mesh strip I1, in a face portion of the filter cr strainer body, thereby providing a reenforcing means E y which serves to addl mechanical strength to the lter or strainer body whereby to increase its ability to withstand fluid pressure in use. Furthermore, when the filter or strainer body is pon the fluid to the interior of the body. so as to cause the fluid to quickly and uniformly spread throughout vthe entire mass of said body.

It has been pointed out that it is preferable to angularly corrugate the metallic mesh strip or rugations aid in producing a better and stronger interlocking together of the mesh plies and loops when the material is compressed to the finished filter or strainer body mass. stood, however, that the mesh strips maybe otherwise roughened to this end, and that even uncorrugated or unroughened mesh strips may be rolled and then compressedto filter or strainer body form, although in such case the resultant body will not be quite so firm or resistant to deformation.

It may also be pointed out that a loose knitted metallic mesh fabric is the most suitable to provide the base material from which the filter or strainer body is made, due to the ease with which it interlocks and binds together when` compressed to the ultimate body form; it is possible, however, to produce a more or less satisfactory lter or strainer body from other types of woven, braided or knitted metallic mesh material.

While I have specifically described my inveni tion as applied to the lformation of foraminous filter or strainer bodies, it will be understood that the same may also be applied for the formation of like bodies for other purposes. l

I am aware that various changes and modifications of form both as to material and finished foraminous body, other than those already hereinabove referred to, could be made, and many apparently widely different embodiments of `this invention could be made without departing from the scope thereof as defined by the following claims. It is therefore intended that all matter contained in the above description or shownin the accompanying drawings shall bev interpreted as illustrative and not in a limiting sense.

I claim:

1. A method of producing a.foraminous body comprising, the provision of a strip of metallic mesh fabric off selected width and length, forming transversely extending corrugations in said strip, rolling said strip upon itself into a substantially cylindrical mass wherein the mesh plies stand edgewise and parallel to the longitudinal axis of said mass, and then compressing said mass by axially applied force whereby to collapse and laterally interlock its corrugate plies and thus consolidate the same into a taining stable foraminous body.

2. A method of producing a foraminous body comprising, the provision of a strip `of metallic mesh fabric of selected Width and length, forming oblique corrugations across the width of said strip, folding said strip upon itself so that the corrugations of the contiguous plies thereof cross one another, rolling the folded strip upon itself into a substantially cylindrical mass wherein the mesh plies stand edgewise and parallel to the longitudinal axis of said mass, and then compressing said mass by axially applied force whereby to consolidate the same into the desired` compacted foraminous body wherein the mesh layers forming the same are collapsed and mutually' strongly interlocked together.

3. A method of producing a foraminous body comprising, the provision of a strip of knitted metallic mesh of selected width and length, forming transversely extending corrugations in said strip, rolling the corrugated strip upon itself into a substantially cylindrical mass wherein the mesh plies stand edgewise and parallel to the longi- It must be underone another, rolling the foldedv strip compacted self-suscomprising, the provision of a strip 3 tudinal axis of said mass, and then compressing said mass by axially applied force whereby to collapse and laterally interlock its corrugate plies and thus consolidate the, same into a compacted self-sustaining stable foraminous body.

4. A methodl of producing a foraminous body of knitted metallic mesh of selected width and length, forming oblique corrugations across the width of said strip, folding said stripupon itself so that the corrugations of the contiguous plies thereof cross upon itself into a substantially cylindrical mass wherein the mesh plies stand edgewise and parallel to the longitudinal axis of said mass, and then compressing said mass by axially applied force whereby to collapse and laterally interlock its corrugate plies and thus consolidate the same intoa stable compacted foraminous body.

5. A method of producing a foraminous body comprising, the provision of a strip of metallic mesh of selected width and length knitted from a fiat ribbon-like metallic strand of selected thickness, forming oblique corrugations across the Width of said strip, folding said strip upon itself so that the corrugations of the contiguous plies thereof cross one another, rolling the folded strip upon itself into a substantially cylindrical mass wherein the mesh plies stand edgewise and parallel to the longitudinal axis of said mass, and then compressing said mass by axially applied force whereby to collapse and laterally interlock its f corrugate plies and thus consolidate the same into a stable compacted foraminous body.

6. A method of producing a'foraminous body comprising, the provision of one strip of mesh fabric of selected width andlength knitted from a comparatively ne metallic strand and the provision of another strip of mesh fabric of selected width and corresponding length knittedfrom a relatively coarse metallic strand, superposing said 7. A method of producing a foraminous bodythe provision of one strip of mesh. n fabric of selected width and length knitted from comprising,

a comparatively ne metallic strand and the provision of another strip of mesh fabric of selected width and corresponding'length knitted from a relatively coarse metallic strand, superposln'g said strips in suitably lapped relation to provide acomposite strip, forming oblique corrugations across the width of the composite strip, folding the corrugated composite strip upon itself so that the corrugations of the contiguous plies thereof cross one another, rolling the folded composite strip upon itself into a substantially cylindrical mass wherein the mesh plies stand edgewise and l parallel to the longitudinal axis of said mass, and

then compressing said mass by axially applied force whereby to collapse and laterally interlock its corrugate plies and thus consolidate the same into a stable compacted foraminous body.

8. A foraminous 4body of self-sustaining substantially stable form comprising a stripof metallic mesh material having corrugations extendlute pliesl are laterally collapsed- 'material being arranged to ing across the same and being rolled intoa cylindrical mass wherein the convolute plies thereof stand edgewlse and-parallel to the longitudinal axis of said mass, said mass being axially compressed into a consolidated body formation whereinthe corrugations of contiguous convoand interlocked together.

,9, A foramlnous body of self-.sustaining substantially stable form comprising a mesh strip 'knitted from metallicstrands, -said strip having convolute plies thereof stand edgewis'e and parallel to the .longitudinal axis of said mass, and

edgewsecollapsed and laterally deformed .and interlocked together inous'lbody. t l

11. Astrainer o fself-sustaining substantially stable body form comprising', apluralltyof mesh strips, one said-strip being knitted from la comparativelyl ne or thin metallic strand and the other from. a relatively coarse metallic strand,

saidstrips being superposed ina suitably lapped relation to provide a composite strip'material, contiguously disposed plies of. said composite strip form a mass wherein saidV plies are collapsed edgewlse into laterally deformed mutually interlocked relation and compressedv into a consolidated f oraminous body, and

said mass being axiallycompressed and its plies irlto a consolidated foramconstituted by the wherein one section of the body constituted by the coarse strand knitted strip is of more open porosity than is the section constituted by the fine strand knitted strip.

12. -A strainer of self-sustaining substantially stable vbody form comprising, a. plurality of mesh strips, one said strip being knitted from a comparatively flne or thin metallic strand and the other from a relatively coarse metallic strand, said strips being superposed in a suitably lapped relation to provide a composite strip material, said composite strip material having oblique corrugations across the same, contiguously disposed pliesv of said composite strip material being arranged to form a. mass with the corrugations of adjacentplies crossing one another and being collapsed edgewise and compressed into a consolidated foraminous body in which the corrugated plies are laterally deformed and mutually interlocked together, and wherein one section of the body constituted by the coarse strand knitted strip is of more open porosity than is the section fine strand knitted strip.

13. A strainer of self-sustaining substantially stable body form comprising," a plurality of mesh strips, one said strip being knitted from a comparatively fine or thin metallic strand and the other from a relatively coarse metallic strand, said strips being superposed in a suitably lapped relation to provide a composite strip material, said composite strip material having oblique corrugations across the same and being folded upon itself so thatthe corrugations of contiguous plies thereof cross one another, said folded strip being rolled on itself to produce a substantially cylindrical mass wherein the plies stand edgewlse and parallel to the axis of said mass, and said plies being collapsed edgewise and compressed into a consolidated'foraminous body in which the corrugated plies are laterally deformed and mutually interlocked together, and wherein the imbedded coarse strand knitted strip reenforces the body mass.

` RALF L. HARTWELL. 

